fix the issue

Author: REBOOTERS

subs/compose/src/main/java/com/engineer/compose/ui/ChatActivity.kt

@@ -26,6 +26,7 @@ import androidx.compose.material3.OutlinedTextField
 import androidx.compose.material3.Surface
 import androidx.compose.material3.Text
 import androidx.compose.runtime.Composable
+import androidx.compose.runtime.collectAsState
 import androidx.compose.runtime.getValue
 import androidx.compose.runtime.livedata.observeAsState
 import androidx.compose.runtime.mutableStateOf
@@ -77,7 +78,8 @@ fun ChatScreen(
     @PreviewParameter(ChatUIWithKeyboardPre::class, 1) chatUIWithKeyboard: ChatUIWithKeyboard
 ) {
     var inputValue by remember { mutableStateOf("") }
-    val msg by viewModel.messageList.observeAsState()
+    val msg by viewModel.messageList.observeAsState(ArrayList<ChatMessage>())
+    val msg1 by viewModel.messages.collectAsState()
     val temp = provideTestChat()
     val kk by viewModel.kkk.observeAsState("11")
 
@@ -89,8 +91,15 @@ fun ChatScreen(
 
     Column(modifier = Modifier.fillMaxSize()) {
         Text(text = kk, modifier = Modifier.size(1.dp))
+        LazyColumn(
+
+        ) {
+            items(msg.size, key = { it }, contentType = {msg[it].sender}) { index ->
+                ChatMessageItem(message = msg[index])
+            }
+        }
         // 消息列表
-        MessageList(messages = msg, modifier = Modifier.weight(1f))
+        MessageList(messages = msg1, modifier = Modifier.weight(1f))
         // 输入框和发送按钮
         InputArea(inputValue = inputValue, viewModel = viewModel, messageText = {
             inputValue = it
@@ -141,15 +150,13 @@ fun InputArea(
 }
 
 @Composable
-fun MessageList(messages: ArrayList<ChatMessage>?, modifier: Modifier) {
+fun MessageList(messages: List<ChatMessage>, modifier: Modifier) {
     Log.d("TAG_TAG", "msg $messages")
-    messages?.let {
-        LazyColumn(
-            modifier = modifier
-        ) {
-            items(messages.size, key = { it }) { index ->
-                ChatMessageItem(message = messages[index])
-            }
+    LazyColumn(
+        modifier = modifier
+    ) {
+        items(messages.size, key = { messages[it].text }) { index ->
+            ChatMessageItem(message = messages[index])
         }
     }
 
@@ -226,4 +233,5 @@ fun ProfilePicture(resId: Int, modifier: Modifier = Modifier) {
 
 fun sendMessage(viewModel: ChatViewModel, message: String) {
     viewModel.query(message)
+//    viewModel.queryFlow(message)
 }

subs/compose/src/main/java/com/engineer/compose/viewmodel/ChatViewModel.kt

@@ -6,6 +6,11 @@ import android.util.Log
 import androidx.lifecycle.LiveData
 import androidx.lifecycle.MutableLiveData
 import androidx.lifecycle.ViewModel
+import androidx.lifecycle.viewModelScope
+import kotlinx.coroutines.delay
+import kotlinx.coroutines.flow.MutableStateFlow
+import kotlinx.coroutines.flow.StateFlow
+import kotlinx.coroutines.launch
 
 class ChatViewModel : ViewModel() {
     private val TAG = "ChatViewModel"
@@ -49,42 +54,86 @@ class ChatViewModel : ViewModel() {
         val mockResponse =
             "天空呈现蓝色的原因主要与光的散射有关。当太阳光进入大气层后，大气中的气体分子和悬浮微粒会对阳光进行散射".toCharArray()
         val sb = StringBuffer()
+        sendData(sb, mockResponse)
+    }
 
-        val subThread = true
-        if (subThread) {
-            Thread {
-                sendData(sb, mockResponse, subThread)
-            }.start()
-        } else {
-            sendData(sb, mockResponse, subThread)
+    private fun sendData(sb: StringBuffer, mockResponse: CharArray) {
+        viewModelScope.launch {
+            for (c in mockResponse) {
+                val history = _messageList.value ?: ArrayList()
+                val lastMsg = history.last()
+                sb.append(c)
+                kkk.postValue(sb.toString())
+                if (lastMsg.sender == "Bot") {
+                    val newMsg = ChatMessage("Bot", sb.toString(), false)
+                    history[history.size -1 ] = newMsg
+
+                    _messageList.value = ArrayList(history)
+
+                } else {
+                    val newMsg = ChatMessage("Bot", sb.toString(), false)
+                    history.add(newMsg)
+                    _messageList.value = history
+                }
+//                _messageList.postValue(history)
+
+                delay(10)
+                Log.d(TAG, "history ${_messageList.value}")
+            }
         }
 
-//
 
     }
 
-    private fun sendData(sb: StringBuffer, mockResponse: CharArray, subThread: Boolean) {
-
-        for (c in mockResponse) {
-            val history = _messageList.value ?: ArrayList()
-            val lastMsg = history.last()
-            sb.append(c)
-            kkk.postValue(sb.toString())
-            if (lastMsg.sender == "Bot") {
-                val newMsg = ChatMessage("Bot", sb.toString(), false)
-                history[history.size - 1] = newMsg
-            } else {
-                val newMsg = ChatMessage("Bot", sb.toString(), false)
-                history.add(newMsg)
+    private val _messages = MutableStateFlow<List<ChatMessage>>(emptyList())
+    val messages: StateFlow<List<ChatMessage>> = _messages
+
+    fun addMessage(message: ChatMessage) {
+        _messages.value = _messages.value + message
+    }
+
+    // 更新特定 index 的消息
+    fun updateMessageAt(index: Int, newMessage: ChatMessage) {
+        _messages.value = _messages.value.toMutableList().apply {
+            if (index in indices) {
+                this[index] = newMessage
             }
-            Log.d(TAG, "history $history")
+        }
+    }
 
-            if (subThread) {
-                _messageList.postValue(history)
-                Thread.sleep(10)
-            } else {
-                _messageList.value = history
+    // 模拟流式添加消息
+    fun startReceivingMessages() {
+        var i = 0
+        val mockResponse =
+            "天空呈现蓝色的原因主要与光的散射有关。当太阳光进入大气层后，大气中的气体分子和悬浮微粒会对阳光进行散射".toCharArray()
+        val sb = StringBuffer()
+
+
+
+        viewModelScope.launch {
+            for (c in mockResponse) {
+                val history = _messages.value ?: ArrayList()
+                val lastMsg = history.last()
+                sb.append(c)
+                kkk.postValue(sb.toString())
+                if (lastMsg.sender == "Bot") {
+                    val newMsg = ChatMessage("Bot", sb.toString(), false)
+                    updateMessageAt(history.size - 1, newMsg)
+                } else {
+                    val newMsg = ChatMessage("Bot", sb.toString(), false)
+                    addMessage(newMsg)
+                }
+                Log.d(TAG, "history $history")
+                delay(20)
             }
+
+
         }
     }
+
+    fun queryFlow(userQuery: String) {
+        val userMsg = ChatMessage("IAM四十二", userQuery, true)
+        addMessage(userMsg)
+        startReceivingMessages()
+    }
 }